Real-Life 'Lizard King' Named for Doors' Jim Morrison

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A lizard the size of a German shepherd once roamed Myanmar, a new
fossil analysis reveals.

The lizard, one of the largest ever known, has been dubbed
Barbaturex morrisoni in honor of The Doors' singer Jim
Morrison, who once wrote a song that included the lyrics, "I am
the lizard king/I can do anything."

"This is a king lizard,
and he was the lizard king, so it just fit," said Jason Head, a
paleontologist at the University of Nebraska-Lincoln who led the
study and gave the ancient lizard its musically inspired moniker.

A lizard of unusual size

In modern times, most lizards are much smaller than the mammals
that share their environment. The few exceptions, such as the
gigantic and toothy Komodo
dragon, live in places where there are few mammals around
(Komodo dragons are found on isolated Indonesian islands, for
example).

B. morrisoni lived in a different world. About 36
million to 40 million years ago, the lizard outweighed the
mammals that shared its mangrove forest home in what is now
Myanmar. It was a gentle giant, with teeth designed for shearing
vegetation, not slicing flesh.

The lizard fossils were first collected during expeditions in the
1970s, but they sat unanalyzed in a museum collection for more
than 30 years until Head and his colleagues decided to study
them. [ 6
Strange Species Discovered in Museums ]

The jaw of B. morrisoni sported a series of ridges that
suggest the animal had some sort of
throat décor such as a skin flap. The lizard might have
looked something like the bearded dragons seen in pet stores
today — except instead of growing to be a foot or so long (30
centimeters), the ancient lizard would have been about 6 feet
(1.8 meters) from nose to tail, Head said. It would have weighed
about 68 pounds (30 kilograms).

"This was a really huge plant-eating lizard, much bigger than
anything alive today," Head told LiveScience.

Komodo dragons can grow 10 feet long (3 meters), but they eat
meat.

Warm world, big lizards

The lizard king discovery helps clear up a mystery about why
lizards don't grow as large today as they once did, Head and his
colleagues found. No one knew whether large plant-eating lizards
are scarce today because they simply can't compete with mammals
or because they're limited by modern-day temperatures. Lizards
are ectothermic, meaning they rely on environmental heat to
keep their body temperature up.

The Eocene epoch, when B. morrisoni lived, was much
warmer than today. Based on the size of the lizard and the
metabolism it would need to get that large, Head and his
colleagues estimate that global average temperatures were 4.5
degrees Fahrenheit (2.5 degrees Celsius) higher than today.

"This was a greenhouse world," Head said. "There was no ice at
the poles. There were higher concentrations of carbon dioxide in
the atmosphere," trapping heat.

In this hot environment, the lizard king outgrew the plant-eating
mammals in its ecosystem as well as many of the meat eaters, Head
said. That growth ability suggests the presence of mammals is not
keeping lizards down today; it's likely lower global
temperatures.

"When we had these very
warm climates in the past, we had much different ecosystems,
and reptiles could compete with mammals much more successfully,"
Head said. Plants may have also flourished more readily in this
steamy climate, providing more food for the herbivorous lizards.

The findings, reported today (June 4) in the journal Proceedings
of the Royal Society B, reveal how ancient ecosystems can hold up
a mirror to modern ones, Head said.

"Paleontology is really vital for understanding not only where
we've come from, but where we are now, and where we're going in
the future," he said.